The present invention relates to computer-based editing systems and methods. More particularly, the present invention relates to a method and system for editing digital information using a comparison buffer.
One of the advantages of computer-based digital editing systems is the ease with which a user can manipulate digital information to achieve a desired result. Such systems permit fine control of common editing and composition processes, and allow the user to view the eventual output during the editing process, and refine or tweak the edited information. An example of such a system is SOFTIMAGE|DS v. 3.0.
Much of the editing done in such a digital editing system involves, or is greatly aided by, comparing an arbitrary image, or sequence of images, to an active image that is being edited. For example, on-line editors currently capture a reference image, which the director of a production has said should set the tone for the rest of the sequence. This reference image is then used to wipe against other shots when color correcting them to ensure that continuity is preserved. Typically, this wiping procedure requires a dedicated digital video effects (DVE) channel on the mixing console.
Similarly, when comparing an off-line edit to an on-line reconstruction of a production, current editing systems require that the off-line edit be digitized and use a DVE channel on a switcher.
Moreover, previous editing systems provide very little flexibility in the manner in which two images can be viewed simultaneously in a viewer.
It is, therefore, desirable to provide a method and system that permits a user to view a comparison image without consuming a DVE channel, and to manipulate or modify the comparison image.
The present invention provides a system and method for editing digital information, such as digital video, digital audio, animations and the like, forming a digital video or multimedia production. In particular, the present invention provides a digital editing system and method having a comparison buffer that permits a number of editing functions, such as color correction, onion-skinning, and wiping, to be accomplished more efficiently.
In a first aspect of the present invention, there is provided a method for editing digital information in a digital editing system. The method starts by displaying an active project, upon which a desired editing function is to be performed, in a viewer. A comparison source is then captured in a comparison buffer for performing the editing function. The captured comparison source is displayed in a comparison view that overlays the project in the viewer. The properties of the comparison view are then adjusted to permit simultaneous viewing of the project and the comparison view in the viewer, to permit the desired editing function to be performed. For example, a sequence of frames, immediately preceding or following a frame of the project, can be captured and displayed transparently to permit an onion-skinning edit function to be performed.
In a further embodiment of the method of the present invention, the size of the comparison view can be adjusted to permit simultaneous viewing of the project view and the comparison view in the viewer. Sizing includes cropping and scaling the comparison view. The comparison view can also be positioned within the comparison view, either by translating the comparison view within the viewer, or scrolling the comparison source within the comparison view. Using these features, a static image can be captured and displayed in the comparison view, and then manipulated through sizing and positioning to permit a color correction function to be performed, such as for wiping an image. Alternatively, an alpha channel of the project can be captured in the comparison view to permit the user to simultaneously view the alpha channel and the RGB channels.
In another embodiment of the method of the present invention, an edge of the comparison view can be highlighted in response to a user input, such as positioning a cursor over the comparison view. This feature allows the user to locate the comparison view within the viewer.
In a further aspect of the present invention, there is provided a method for processing a digital video production in a digital post-production editing system. A digitally reconstructed on-line project is displayed in a viewer. An off-line project, from a external video source, is captured to a comparison buffer attached to the viewer. Typically, the off-line project is the original, unprocessed, work edit of the final production. The off-line project is displayed in the viewer, and overlays the on-line project. The displayed off-line project is sized to permit simultaneous viewing of the on-line project and the off-line project in the viewer. The on-line and off-line projects can then be compared to detect undesired variations, such as dropped frames and timing shifts, in the on-line project, and to correct the undesired variations. During the comparison process, the external video source is under the control of the digital post-production editing system.
To accomplish the above method, the present invention provides a digital post-production editing system. The system includes a viewer for displaying an active project. A comparison buffer captures a desired comparison source, which is displayed within a comparison view in the viewer. A sizing tool, such as handles at the edges of the comparison view, permits the comparison view to be cropped or scaled to permit simultaneous viewing of the project and the comparison view in the viewer. A positioning tool, such as dragging with a mouse, allows the comparison view to be moved within the viewer, and the comparison source to be scrolled within the comparison view. Conventional editing tools then permit the desired editing function to be performed.